"It's difficult to determine the exact number of dead pigs buried as they have decayed, but there must be so many as the stink was so strong that it caused several excavation workers to throw up," said the source, who had also witnessed the excavation. Earlier, he had told authorities that "tens of thousands of dead pigs" had been buried in the area. [...]

But the discovery was nevertheless alarming as it came just four years after more than 6,000 dead pigs were dumped into local waterways in Jiaxing, also in Zhejiang province. In March 2013, the rotting carcasses were found in Shanghai's Huangpu River, the source of drinking water for the metropolis's 23 million residents. [...]

"Once the carcasses decay, pollutants will certainly make their way into the soil and the reservoir," said one villager who asked for anonymity because they have been told by authorities not to speak to the media.

Local authorities haven't tested the water in the area's waterways, including the reservoir in question, for possible contamination. It's unknown how many residents drink water from the reservoir and streams nearby. [...]

The three sites on Dayin mountain have been cordoned off shortly after excavation work began. But drone footage obtained by Caixin on Wednesday shows workers in protective gear putting large black objects into cardboard boxes next to mounds of earth piled up after digging up several large pits.

One Xinghong employee told Caixin that the dark objects recovered were decayed pig carcasses, and workers had taken boxes with animal remnants back to the company for cremation. The wastewater and sludge left in the pits was so thick that they had to use large pipes to clean it up, he said.